1. Field of the Invention
The present invention relates to a honeycomb structure and a manufacturing method thereof. More particularly, it relates to a honeycomb structure onto which a large amount of catalyst can be carried while suppressing an increase in pressure drop and which can suitably be used as a catalyst carrier, and a honeycomb structure manufacturing method by which such a honeycomb structure can be manufactured.
2. Description of Related Art
Heretofore, there have been suggested exhaust gas purification devices where a catalyst for purification is carried onto a catalyst carrier, to purify components under purification included in exhaust gases discharged from engines for a car and for a construction machine, an industrial stationary engine, a combustion apparatus, and the like. Examples of the components under purification include carbon monoxides (CO), hydrocarbons (HC), nitrogen oxides (NOx), and sulfur oxides (SOx). As a catalyst carrier for such an exhaust gas purification device, there is used, for example, a honeycomb structure including porous partition walls by which a plurality of cells that become through channels of a fluid are partitioned (e.g., Patent Documents 1 and 2). The catalyst for purification is carried onto the surfaces of the partition walls of the honeycomb structure and the insides of pores of the porous partition walls.
The honeycomb structure can be manufactured by, for example, the following manufacturing method. First, forming raw materials containing a ceramic raw material are mixed and kneaded to obtain a kneaded clay. The obtained kneaded clay is extruded and formed into a honeycomb shape to obtain a honeycomb formed article. The obtained honeycomb formed article is dried and fired, whereby the honeycomb structure can be manufactured. Moreover, as a manufacturing method of a porous ceramic having a high porosity and a large strength, the following manufacturing method and the like have been disclosed. The manufacturing method includes a step of forming a mixture containing water absorptive polymer particles having an amount of water to be absorbed at a pressure of 980 Pa in a range of 5 to 30 ml/g, the ceramic raw material and water, and a step of heating and firing the obtained formed article (e.g., Patent Document 3).    [Patent Document 1] JP-A-2009-242133    [Patent Document 2] Japanese Patent No. 4246475    [Patent Document 3] Japanese Patent No. 4540094